Method for machining rollers and other objects using laser light and equipment for machining

ABSTRACT

By irradiating with high-intensity pulsed laser light of wavelength 9.0μ to 11.0μ the organic film on rollers, and specifically, the film on photosensitive drums, fixing rollers, rubber rollers, and magnetic rollers used in photocopying equipment, printers, facsimile machines, and other equipment, said film can be removed from the roller surface without damaging the underlying metal layer in any way. Metal cylinders from which film has been removed by this method can either be reused as is, or may be recoated, and then, reused as rollers in photocopying equipment, printers, and facsimile machines. 
     Furthermore, a method is disclosed, wherein laser light irradiation is used to remove film from the surface of various rollers, as is equipment for roller machining and processing.

FIELD OF THE TECHNOLOGY

The present invention relates to a method for removal of organic thinfilm from a roller, and equipment for implementing this method.Specifically, the present invention relates to a method and equipmentwhich use laser light to effectively remove organic film from thephotosensitive drums used in photocopy machines, printers and facsimileequipment, fixing rollers, rubber rollers, magnetic rollers, and variousother types of rollers. It further relates to a method and the necessaryequipment to use laser light to process defective products generated inthe process of roller manufacture, as well as various types of usedrollers, enabling reuse of said rollers.

BACKGROUND OF THE INVENTION

Rollers are used in a variety of machines and devices. For instance,photosensitive drums, fixing rollers, rubber rollers, and magneticrollers are used in photocopy machines, printers, facsimile machines,and other equipment. In general, such rollers are either cylinders witha high degree of concentricity formed of aluminum or some other metal,or else a similar metal cylinder, the surface of which has been treatedin various methods and covered with a film. Fixing rollers often consistof aluminum cylinders with a fluoride resin coating; similarly, rubberrollers are often aluminum cylinders with a rubber coating.Photosensitive drums generally consist of a cylinder of aluminum or someother metal, to which an undercoating is applied, followed by coatingwith a layer containing titanium oxide or some similar material, apolycarbonate resin layer, and a film. Magnetic rollers are used tosupply toner; often a metal cylinder is used without furthermodification.

The following problems with these rollers have been identified, relatingto roller manufacturing and use:

(1) When forming the film on the metal cylinder surface, the metalcylinder is immersed in a container of liquid from which a film is to beformed, and said metal cylinder is then pulled upward. At this time, thebottom part of the immersed cylinder is completely covered, but theupper part remains uncovered. For this reason, the roller is unbalanced.It therefore becomes necessary to remove part of the film on the bottom,in order to finish the roller so that it is balanced.

(2) When magnetic rollers used for toner supply are used for longperiods of time, styrene resins and other toner components tend toadhere to the roller surface and accumulate, so that an undesirable filmis formed. Such an undesirable film on the magnetic roller adverselyaffects the magnetic and electrical properties of the toner, anddegrades the quality of the resulting image.

(3) When rollers are used for extended periods of time, the film on theroller surface may receive damage in a non-uniform manner, or foreignmatter may adhere to its surface. As a result, multiple sheets of paperfor recording may be fed into the mechanism, the quality of photocopiesmay be deteriorated, or other problems may occur. Rollers which giverise to such problems during equipment use must be replaced, and ingeneral, rollers which have been replaced cannot be refurbished and,therefore, are discarded. Because number of rollers which are thusdiscarded is very large, a means for recovery and refurbishing of therollers is desired.

(4) In the process of manufacturing various rollers, such asphotosensitive drums, fixing rollers, and rubber rollers which are usedin photocopiers, printers and facsimile machines, defective productsoccur as a consequence of film formation processes. The rate ofoccurrence of such defective items is said to be at least 10%, andbecause it is not easy to recover and reuse such defective rollers, theyare discarded. In conjunction with rollers discarded after replacementas described in (3) above, this represents a considerable waste ofresources, and an appropriate means of roller reuse is sought.

(5) When forming a film on the surface of a roller during rollermanufacturing, the film thickness may be non-uniform, or the filmsurface may be irregular, or pinholes may be present in the film.

Measures currently adopted to resolve the above problems, and the statussurrounding such measures, are as follows.

With regard to problem (1), the excess film at the bottom of thecylinder is either scraped away using a hair brush or other instrument,or is removed by chemical etching, followed by wiping using a solvent.These methods take time and also use chemical reagents, such thatpost-treatment becomes complicated. As a result, a dry process whichdoes not rely on chemical means is strongly desired. Furthermore, theprocessing methods currently in use are expensive. In light of thesedisadvantages, a method for effective removal of excess film at thebottom of cylinders is sought.

With respect to problem (2), no appropriate processing method isavailable, and such rollers are discarded. That is, at present noappropriate method exists for removing the film formed by the adhesionand accumulation of toner components and other materials, such thatmagnetic rollers are replaced with new rollers, and the old rollers arediscarded. This is a waste of resources, and some means of reclaimingand recycling such rollers is desired.

With respect to problems (3) and (4), there are, as in the case of (2)above, no appropriate countermeasures available, and the rollers arediscarded. This too is a waste of resources, and a means of reusingrollers is desired. With respect to problem (5), tape polishing is usedin some cases. That is, protrusions are polished in order to make thesurface smooth. However, such tape polishing may leave "abrasion marks"in the roller film, such that heat treatment is necessary afterpolishing, introducing yet another process and raising costs. For thisreason, tape polishing is used only in some cases, and most defectiveproducts are discarded. Consequently, there is an urgent demand for aneffective means of obtaining film with uniform thickness.

SUMMARY OF THE INVENTION

The objectives of the present invention include resolution of problemsrelating to organic films on rollers, and specifically, resolution ofthe problems described above relating to the photosensitive drums,fixing rollers, rubber rollers, magnetic rollers, and other rollers usedin photocopy equipment, printers, facsimile machines, and otherequipment, enabling effective reclamation of said rollers, as well asequipment for the implementation of this method. Further objectives ofthe present invention are methods and equipment for the effectiveprocessing of defective products arising in the process of rollermanufacturing and of rollers which through prolonged use are no longeradequate for use, to enable reuse of said rollers.

Of the above-described problems, problems (1) through (4) involve how toremove film on the roller surface. That is, it is sufficient to be ableto effectively remove film on the roller surface. In the case ofmagnetic rollers, the roller can be reused without further treatmentonce the film is removed; in the case of rollers which are used afterforming a film on the surface, the film can first be removed and thenanother film formed. In the case of problem (5), on the other hand, amethod is sought for effectively smoothing and producing uniform filmson a roller surface, to replace tape polishing.

From an engineering standpoint, the problems faced by the presentinvention may be reduced to the problems of a method for effectiveremoval of films from roller surfaces, and of equipment to implementthat method. The films to be removed by the present invention areorganic films on roller surfaces, such as films of fluoride resins,polystyrene-base resins used as components in toners, polyearbonates,and rubbers.

The inventors of the present invention conducted extensive research onmethods and equipment for effective removal of films on roller surfaces,and discovered that when a specific type of laser light is used, saidfilms can be removed effectively. Based on this discovery, theycompleted the present invention.

In removing part or all of the film from various rollers, andspecifically from photosensitive drums, fixing rollers, rubber rollers,magnetic rollers, and other rollers, such as those used in photocopiers,printers, and facsimile machines, this method as well as the equipmentfor removal of films from rollers is characterized by the irradiation ofhigh-intensity pulsed laser light of wavelength 9.0 to 11.0 micron, andin particular, of high-intensity pulsed laser light at a wavelength of9.3 micron.

The equipment for film removal comprises: first, a roller processingapparatus consisting of a mechanism for holding and rotating variousrollers, such as photosensitive drums, fixing rollers, rubber rollers,and magnetic rollers for use in photocopying machines, printers andfacsimile equipment; a laser oscillator and laser light irradiationmechanism; an air blower for removal of the soot of film residue andother material generated during laser irradiation; and a suction dustcollection mechanism; second, a roller machining apparatus which employsa concave lens to broaden the optical path of the laser light and acylindrical lens to form the beam into a long, thin rectangular-shapedbeam with which the roller is irradiated. Third, a roller processingapparatus, which during laser light irradiation, combines totalreflection mirrors and semi-transparent mirrors arranged in stages tobreak the beam of laser light into multiple beams. Fourth, a rollerprocessing apparatus capable of determining the end of processing, andequipped with either an audio detector to detect the sound emittedduring laser irradiation, or with an optical system to observe the stateof the roller surface, or with both an audio detector and an opticalsystem.

In the past, there have been almost no methods for effectively removingfilm from a roller without damaging the underlying metal layer. Ingeneral, when attempting to remove films or other materials adhering toa roller surface, mechanical methods of removal are conceivable. Theseinclude, for instance, machining, blasting, polishing, and water jetmethods. Machining methods involve cutting the film; however in order tocompletely remove the film, the cutting will inevitably proceed to themetal layer. After one or several such machinings, the metal layerbecomes extremely thin, such that strict limits are imposed on thepossibility of reuse. In blasting methods where the workpiece to beprocessed is sprayed with fine abrasive particles, and also in polishingmethods, the underlying metal layer is damaged, and therefore, suchmethods are also unsuitable. Moreover, in water jet methods, if thewater pressure used is low, the film removal is insufficient, whereas ifit is too great, the metal cylinder may be cut. Thus, water jet methodsare not suitable for effective removal of films of differentcompositions. In all cases, it is as a practical matter, extremelydifficult to effectively remove only the film without damaging theunderlying metal layer using mechanical methods.

On the other hand, film dissolution methods in which a solvent is usedto dissolve the film are also conceivable. However, it is extremelydifficult to select a solvent for use in dissolving films of variouscompositions. Moreover, even if dissolution were possible, it would benecessary to recover the solvent and complex processes would be involvedin roller reclamation, making such methods impractical.

In contrast, irradiation with high-intensity pulsed laser light in the9.0 to 11.0 micron wavelength range enables easy removal of films fromroller surfaces, and is a dry process. It therefore offers significantadvantages.

Laser light has a high intrinsic energy density, and the direction andduration of laser light emission can be controlled electrically.Furthermore, by combining a laser with a mask module, expander or otheroptical system, the shape of the laser-irradiated area can bearbitrarily set. Moreover, laser light does not make physical contactwith the workpiece, and the process of machining using laser light is adry process, such that the laser light method offers the advantage ofease in handling compared with chemical and mechanical methods. For thisreason laser light machining is suitable for industrial applications.

The use of laser light to remove films is itself already known in theprior art. For instance, the removal by laser light of metal, metaloxide, or other inorganic materials is described in Laid-Open Patents58-179586, 59-73189, 59-153591, 1-95814, and 5-337660, etc. Techniquesto use laser light to remove organic films from various rollers, such asthe photosensitive drums, fixing rollers, and magnetic rollers used inphotocopying equipment, printers, and facsimile machines are describedin Laid-Open Patents 3-144458, 5-34934, and 6-344160. These techniquesemploy YAG lasers and carbon dioxide gas lasers, and in particular,continuous carbon dioxide gas lasers, as sources of laser light.

Lasers which are known as practical sources of high output includecarbon dioxide gas lasers, excimer lasers, and YAG lasers (InterLinguaNote - Sic. Listed in exact order as mentioned in the original). Amongthese, YAG lasers have the disadvantage of causing some melting of themetal layer which constitutes the roller substrate. Excimer lasers arenot able to remove fluoride resin films. Finally, continuous carbondioxide laser light has the disadvantage of poor machining efficiency.Pulsed laser light in the 9.0 to 11.0 micron wavelength range canefficiently remove films from roller surfaces, and therefore, thepresent invention uses high-intensity pulsed laser light in the 9.0 to11.0 micron wavelength range.

The laser oscillator is inherently a pulsed device; however the desireto use continuous laser light has led to widespread use ofcontinuous-wave-type lasers. On the other hand, some lasers are not ableto produce continuous-wave output due to the mechanism of excitation. Insuch cases, the intensity of the emitted laser light is great, and theoutput is a high-intensity pulsed laser light.

In the present invention, high-intensity pulsed laser light in thewavelength range from 9.0 to 11.0 micron is used. Actual examples oflaser light used in the present invention are high-intensity pulsedlaser light at a wavelength of 9.3 micron, and high-intensity pulsedlaser light at a wavelength of 10.6 micron. These kinds ofhigh-intensity pulsed laser light can be obtained, for instance, from alaser emission device ("Impact Laser") manufactured by Sumitomo HeavyIndustries, Ltd. The laser light emitted by this "Impact Laser" is apulsed laser light and has a high emission intensity.

Normally 9.3 micron wavelength high-intensity laser light is obtainedfrom the "Impact Laser." By changing the coating material of the frontmirror and rear mirror of the laser oscillator, however, the wavelengthof the light emitted by the oscillator can be varied in the range of 9.0to 11.0 micron.

By using high-intensity pulsed laser light at wavelengths between 9.0and 11.0 micron, organic films on various types of rollers can beremoved effectively. By using said laser light, it has become possibleto effectively remove films from various types of rollers. Through thepresent invention, accurate film removal from rollers becomes possibleand in a short period of time, and the economic benefits arising fromthe present invention are very significant.

Continuous laser light from carbon dioxide gas lasers, which arenormally capable of high output, suffers from the disadvantage of atendency for the film to be "scorched" or "burned." For instance, whenirradiating a photosensitive drum with continuous-wave carbon dioxidegas laser light, the film may peel in places, and smoke and burns mayoccur, making the process unsuitable for the purpose of drumrefurbishing and reuse. With respect to energy efficiency as well, whenusing a continuous-wave carbon dioxide gas laser, 6 kW of power isrequired to obtain an operating efficiency equivalent to that of 400 Wof power using high-intensity pulsed laser light.

When removing organic film from a roller surface, high-intensity pulsedlaser light at a wavelength between 9.0 and 11.0 micron is effective.This is inferred to be due to both, the fact that a large amount ofenergy is delivered in a brief instant because high-intensity pulsedlaser light is used, and the fact that laser light in the wavelengthrange from 9.3 to 11.0 micron is efficiently absorbed by organic films.

When using laser light for processing, the workpiece must be efficientlyirradiated by the laser light. To this end, in addition to the obviousmeasure of using several sources of laser light, it is also effective touse either a method in which the laser light emitted by a laser lightsource is diffused using a concave lens, and then formed into a morerectangular beam using a cylindrical lens, or else a method forseparating the laser light into multiple beams using an optical systemconsisting of semi-transparent mirrors and total reflection mirrorsarranged in stages, in order to uniformly irradiate the entire rollersurface in the roller length direction with laser light, or else acombination of the above methods.

Moreover, by rotating the roller to be processed while irradiating itwith laser light, the laser light can be efficiently irradiated on theroller surface.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a block diagram of the basic construction of the equipmentfor film removal according to the present invention;

FIG. 2 shows a block diagram of an embodiment of film removal apparatusaccording to the present invention;

FIG. 3 shows a block diagram which illustrates by example, the laserlight irradiation system of the film removal apparatus according to thepresent invention; and

FIG. 4 shows a block diagram of the lens unit of the laser lightirradiation system according to the present invention.

REFERENCE NUMBERS

1, 1a, 1b Laser light oscillators

2 Laser light irradiation device

3 Roller

4 Roller retention and rotation mechanism

5 Driving apparatus

6 Blower mechanism

7 Gas generator

8 Suction dust collection mechanism

9 System controller

10a, 10b Laser controllers

11 Audio sensor

12 Audio detector

13 CCD camera

14 Monitor

15 Image processing unit

16a to 16d Total reflection mirrors

17a, 17d, 18a, 18c, 18f, 18h Semi-transparent mirrors

17b, 17c, 18b, 18d, 18e, 18g Total reflection mirrors

19a to 19h Concave lenses

20a to 20h Cylindrical lenses

PREFERRED EMBODIMENTS OF THE INVENTION

One embodiment of the present invention is as follows. The basicconfiguration of equipment for film removal comprises a retention androtation mechanism for holding and rotating the various rollers used inphotocopying equipment and other equipment, a mechanism for laser lightgeneration and irradiation, and a blower mechanism and suction dustcollection mechanism for removing soot and the film residue arisingduring laser light irradiation.

In FIG. 1, 1 is a laser oscillator. Laser light emitted by the laseroscillator is used to irradiate a roller 3 by the laser lightirradiation device 2. Said roller 3 is loaded into a roller retentionand rotation mechanism 4, and is rotated by a driving apparatus 5. Inorder to remove the soot and film residue, which is generated duringlaser light irradiation of the film on the roller surface, gas is blownby a gas blower mechanism 6. Said gas is supplied by a gas generator 7.It is convenient to supply gas using either compressed air or a gastank. Said gas used may be ordinary air, however the use of argon,helium, nitrogen, or some other inert gas is desirable.

When irradiating a roller with laser light, in general, a suction dustcollector 8 is installed; in the present invention, also, a suction dustcollector can be used to remove soot, film residue, and other material,however additional use of a gas blower is effective.

When irradiating the roller with laser light, the emitted laser light isdiffused by a concave lens, formed into a rectangular beam by acylindrical lens, and irradiated on the roller surface. That is, thelaser light beam in FIG. 4 is broadened by the concave lens 19. Thebroadened laser light beam is next guided to the cylindrical lens 20,where it is converted into a long, narrow rectangular-shaped beam oflaser light. This rectangular beam of laser light is then irradiated onthe object to be irradiated, namely, roller 3. Here, the width andlength of the laser light beam irradiated on the roller can be adjustedby changing the distance between the laser irradiation device and theroller.

When processing long rollers in particular, the laser light may bedivided into multiple beams in order that the entire roller surface canbe irradiated uniformly in the length direction. The following is anexample of an example of such a system, with reference to FIG. 3. Inthis explanation, the laser light is divided into eight laser lightbeams, however in other embodiments, any other number of beams may beused. Laser light emitted by the laser oscillator 1a is guided to thetotal reflection mirrors, 16a and 16b. The laser light further passesthrough the semi-transparent mirror 17a, which transmits 50% of thelight and reflects 50%; the transmitted light is guided to thesemi-transparent mirror 18a, and the reflected light to the totalreflection mirror 17b. Of the laser light guided to the semi-transparentmirror 18a, 50% is transmitted and passes through lenses, 19a and 20a,before reaching roller 3. The other 50% is reflected and guided to thetotal reflection mirror 18b, then passes through the lenses 19b and 20bbefore reaching the roller 3.

Thus, by using an optical system combining multiple stages ofsemi-transparent mirrors and total reflection mirrors, the laser lightmay be divided into fourths and guided to the lenses, 19a and 20a, to,19d and 20d. The laser light emitted by the laser light oscillator 1b isdivided into fourths by a similar process to reach the lenses, 19e and20e, to, 19h and 20h, such that a total of eight laser light beams areobtained.

The method for holding or retaining the roller may employ either ahorizontal roller orientation as shown in the example, or a verticalorientation. In this case, of course, laser light irradiation occursfrom a horizontal direction.

As part of the laser light irradiation process, the method of dividingthe laser light into several beams has been described, however thepresent invention is not limited to this method. A roller may also beirradiated with a single beam of laser light. In this case, the laserlight will be irradiated on only some parts of the roller, andtherefore, it is desirable that, while rotating the roller, the rollereither be moved laterally, or else the laser light be moved laterally inthe roller direction of the length. Of course, the method of moving thelaser light in the roller direction of the length can also be applied tothe aforementioned case in which the laser light is divided intomultiple beams.

Automated execution of the film removal process is also possible. Here,an important issue is the method used to determine the end of theprocess of film removal. It is known that when irradiating a roller withlaser light, the sound emitted during laser light irradiation becomessmaller as the film is removed, and the area of the underlying metallayer becomes greater. This phenomenon may be utilized to detect thesound emitted during laser light irradiation, using it as a signal todetermine the end of the removal process.

In addition, a camera may be used to determine the state of the rollersurface as an image, and computer image processing may be used to decidewhether the film has been removed or not. By using image processing tocause the metal layer to appear white and the film areas to appearblack, the completion of the film removal process may be determinedeasily and reliably. Either of these two methods may be usedindependently, or the two may be used in combination.

In FIG. 2, the sound emitted during laser light irradiation is measuredby sensor 11 and audio detector 12. In addition, the surface state iscaptured by a CCD camera 13, and can be observed on a monitor 14. Thecaptured image data is subjected to image processing on a computer 15.The sound is converted into an appropriate electrical signal, and thedata resulting from image processing is also converted into electricalsignals at an appropriate brightness and transmitted to the systemcontroller 9, such that any necessary measures can be taken to controlthe lasers, stop the roller rotation, or take other actions.

Because the coating layer on rubber rollers is thicker than the coveringon other types of rollers, such rollers may be subjected to machining orother preprocessing, to cut the rubber layer in advance, so as to reducethe laser light irradiation time.

One specific embodiment of the present invention is herein explainedwith reference to FIG. 2. Roller 3 is mounted on a retention androtation mechanism 4, and said roller is rotated by a rotation apparatus5. Laser light is emitted from the laser oscillators, 1a and 1b. Theirradiation of laser light is controlled by controllers, 10a and 10b.The emitted laser light passes through an optical system comprisingtotal reflection mirrors, semi-transparent mirrors, concave lenses, andcylindrical lenses, before irradiation on roller 3. This optical systemis in essence identical to the optical systems described in FIG. 3 andFIG. 4.

When the laser light is irradiated on the roller, the film on the rollersurface is gradually removed. The sound emitted during this process iscaptured by sensor 11 and audio detector 12, becoming an electricalsignal which is sent to the system controller 9, which controls theentire system. On the other hand, image processed data corresponding tothe surface state of roller 3 is captured by the CCD camera 13 andpasses through monitor 14, before being subjected to image processing oncomputer 15. The image-processed data is sent, as electrical signalscorresponding to brightness, to system controller 9. When the signalbased on the sound at detector 12 falls below a certain level, it iscompared with the brightness signals obtained from camera 13, and thecompletion of film removal from roller 3 is confirmed, and controller 9sends signals to stop the laser irradiation and roller rotation, thiscompleting the series of tasks.

The soot, film residue, and other materials generated in the process offilm removal is removed by blowing gas using the suction dust collectionmechanism 8 and the gas blower mechanism 6. The gas is supplied by acompressor or from a tank 7.

Embodiment 1

A fixing roller comprised of an aluminum cylinder 300 mm in length and30 mm in diameter and covered with a 12 micron thick Teflon coating wasmounted on the roller retention and rotation mechanism 4 in FIG. 2. Thedriving apparatus 5 was used to rotate the roller at a linear velocityof 2,000 mm/minute. Using the "Impact Laser" laser oscillatormanufactured by Sumitomo Heavy Industries, Ltd., 200 W of laser light ofwavelength 9.3 micron was emitted from the two emitters, 1a and 1b, andafter the light was divided into eight beams, the light was irradiatedon the photosensitive drum. The area irradiated by a single beam oflaser light was a rectangle 0.1 mm wide and 40 mm in length.

When the laser light was irradiated on the roller, a large cracklingsound was emitted, and the film on the roller was observed to be removedgradually. As the film was removed, the emitted sound became smaller. Atthe same time, the data obtained from image processing of the image datacaptured by the camera showed clearly that the black area vanished,while the white area expanded, indicating that the film was beingremoved. Soot and film residue were generated near the roller and thesewere removed by blowing nitrogen supplied from the tank 7 using theblowing mechanism 6.

When laser light was irradiated for 7 seconds, the emitted sound wasreduced and the results of image processing also indicated that the filmhad been removed. The laser light oscillation and roller rotation werestopped, the roller was removed from the equipment, and on closeinspection of the roller surface with the unaided eye and using amagnifying glass, the Teflon film was determined to have been completelyremoved.

After removing the film in this manner, the roller was recoated and usedagain in photocopying equipment, and no problems were encountered.

Embodiment 2

An aluminum photosensitive drum 300 mm in length and 80 mm in diameterwas mounted on the roller retention and rotation mechanism 4 in FIG. 2,similar to the procedure of Embodiment 1. The driving apparatus 5 wasused to rotate said drum at a linear velocity of 400 mm/minute. Usingthe "Impact Laser" laser oscillator manufactured by Sumitomo HeavyIndustries, Ltd., 200 W of laser light of wavelength 9.3 micron wasemitted from the two emitters, 1a and 1b, and after the light wasdivided into eight beams, the light was irradiated on the photosensitivedrum. The area irradiated by a single beam of laser light was arectangle 0.1 mm wide and 40 mm in length.

When the light was irradiated on the drum, a similar crackling sound wasgenerated, and the film on the drum surface was observed to be graduallyremoved. Because the composition of the film on the photosensitive drumsurface differed from that of the film on the fixing roller, the soundgenerated during laser irradiation was somewhat louder than thatgenerated in the case of the fixing roller. As the film was removed,soot and film residue were generated; these were removed by blowingnitrogen together with suction.

On continuing the laser light irradiation for 18 seconds, the soundbecame small, and the results of image processing also revealed that thefilm had been removed. The laser light irradiation and drum rotationwere stopped, the drum was removed from the equipment, and on closeinspection of the roller surface with the unaided eye and using amagnifying glass, the film was determined to have been completelyremoved.

After removing the film in this manner, the drum was recoated and usedagain in photocopying equipment, and no problems were encountered.

Embodiment 3

A rubber roller consisting of an aluminum cylinder 300 mm in length and45 mm in diameter and coated with 1 mm of rubber was mounted on theroller retention and rotation mechanism 4 in FIG. 2, similar to theprocedure of Embodiment 1. The driving apparatus 5 was used to rotatethe roller at a linear velocity of 1,000 mm/minute. Using the "ImpactLaser," 200 W of high-intensity pulsed laser light of wavelength 10.6micron was emitted from the two emitters, 1a and 1b, and after the lightwas divided into eight beams, the light was irradiated on the roller.The area irradiated by a single beam of laser light was a rectangle 0.1mm wide and 40 mm in length.

When the light was irradiated on the drum, a large sound was generated,and the film on the roller surface was observed to be gradually removed.As the film was removed, the sound became smaller. After the laserirradiation lasted for 25 seconds, the sound became small, and theresults of image processing of an image from the camera indicated thatthere were no black areas and that the film had been removed. Here, sootand film residue were generated near the roller; these were removed byblowing nitrogen.

The laser light irradiation and roller rotation were stopped, the rollerwas removed from the equipment, and on close inspection of the rollersurface with the unaided eye and using a magnifying glass, the rubberfilm was determined to have been completely removed.

After removing the film in this manner, the roller was recoated withrubber and used again in photocopying equipment, and no problems wereencountered.

Embodiment 4

A magnetic roller consisting of an aluminum cylinder 300 mm in lengthand 25 mm in diameter and coated with a resin film based on polystyrene,was mounted on the roller retention and rotation mechanism 4 in FIG. 2,similar to the procedure of Embodiment 1. The driving apparatus 5 wasused to rotate said roller at a linear velocity of 400 mm/minute.High-intensity pulsed laser light of wavelength 9.3 micron was emittedfrom the two emitters, 1a and 1b, and after the light was divided intoeight beams, the light was irradiated on the resin film on the roller.The energy density incident on the roller was 3 J/cm2, the film on theroller surface was observed, and three pulses of laser light were used.It was observed that the laser light was irradiated on the roller to begradually removed. As the film was removed, soot and film residue weregenerated near the roller; these were removed by blowing nitrogen.

On close inspection of the surface of the roller with the unaided eyeand using a magnifying glass, the resin film was determined to have beencompletely removed. After removing the film in this manner, the rollerwas used again in photocopying equipment, and no problems wereencountered.

Comparative Example 1

In Embodiment 3, the rubber film on the rubber roller was irradiatedwith laser light under identical conditions, except that continuous-wavecarbon dioxide gas laser light with an output of 4 kW was used. Afterirradiation for approximately 45 seconds, the rubber was partiallyremoved; however on close inspection of the roller surface afterirradiation, burn marks were found on the rubber film.

Field of Industrial Application

By using high-intensity pulsed laser light with a wavelength range from9.0 to 11.0 micron to irradiate organic films on rollers, and inparticular, the films on photosensitive drums, fixing rollers, rubberrollers, magnetic rollers, and other rollers used in photocopyingequipment, printers, and facsimile machines, it is possible to removesaid film without causing any damage to the underlying metal layer.Metal cylinders which have been subjected to such processing may eitherbe reused, either without further treatment or after recoating, inphotocopying equipment, printers, facsimile machines, and otherequipment.

I claim:
 1. A method for removing a portion of an organic film from thesurface of a roller, comprising the step of irradiating the portion ofthe film to be removed from the roller surface with high-intensitypulsed laser light of a wavelength of 9.0 micron to 11.0 micron;whereinthe step of irradiating further comprises dividing a laser light beaminto a plurality of sections with at least one half mirror and at leastone full mirror; broadening each section with a concave lens to producea broadened section, shaping each broadened section to produce arectangular shaped beam; and irradiating a rotating roller along alongitudinal axis thereof with the elongated rectangular shaped beam toremove the portion of an organic film from the surface of the roller. 2.The method for removing film from rollers according to claim 1, whereinthe high-intensity pulsed laser light used to irradiate the roller has awavelength of 9.3 micron.
 3. A method of removing a part of an organicfilm from a surface of a roller according claim 2, further comprisingthe steps of detecting with a sensor sounds emitted during the step ofirradiating, converting the detected sounds into a sound signal, andstopping the laser light irradiation and roller rotation when the soundsignal becomes lower than a predetermined level.
 4. A method accordingto claim 2, wherein said step of irradiating uses multiple laser lightsources.
 5. A method of removing a part of an organic film from asurface of a roller according claim 4, further comprising the steps ofdetecting with a sensor sounds emitted during the step of irradiating,converting the detected sounds into a sound signal, and stopping thelaser light irradiation and roller rotation when the sound signalbecomes lower than a predetermined level.
 6. A method of removing a partof an organic film from a surface of a roller according to claim 4,further comprising the steps of making an image of a roller surface witha CCD camera during the step of irradiating, processing the image toobtain a brightness signal, and stopping the laser light irradiation androller rotation when the brightness signal has a predetermined value. 7.A method of removing a part of an organic film from a surface of aroller according to claim 4, further comprising the steps of detectingwith a sensor sounds emitted during the step of irradiating, convertingthe detected sounds into a sound signal, making an image of a rollersurface with a CCD camera during the step of irradiating, processing theimage to obtain a brightness signal, and stopping the laser lightirradiation and roller rotation when the sound signal becomes lower thana predetermined level and when the brightness signal has a predeterminedvalue.
 8. A method of removing a part of an organic film from a surfaceof a roller according to claim 2, further comprising the steps ofdetecting with a sensor sounds emitted during the step of irradiating,converting the detected sounds into a sound signal, making an image of aroller surface with a CCD camera during the step of irradiating,processing the image to obtain a brightness signal, and stopping thelaser light irradiation and roller rotation when the sound signalbecomes lower than a predetermined level and when the brightness signalhas a predetermined value.
 9. A method according to claim 1, whereinsaid roller is selected from the group consisting of photosensitivedrums, fixing rollers, rubber rollers, and magnetic rollers used inphotocopying equipment, printers, facsimile machines, and otherequipment.
 10. A method according to claim 9, wherein the high-intensitypulsed laser light used to irradiate a roller is of a wavelength of 9.3.11. A method of removing a part of an organic film from a surface of aroller according claim 10, further comprising the steps of detectingwith a sensor sounds emitted during the step of irradiating, convertingthe detected sounds into a sound signal, and stopping the laser lightirradiation and roller rotation when the sound signal becomes lower thana predetermined level.
 12. A method according to claim 10, wherein saidstep of irradiating uses multiple laser light sources.
 13. A method ofremoving a part of an organic film from a surface of a roller accordingto claim 12, further comprising the steps of detecting with a sensorsounds emitted during the step of irradiating, converting the detectedsounds into a sound signal, making an image of a roller surface with aCCD camera during the step of irradiating, processing the image toobtain a brightness signal, and stopping the laser light irradiation androller rotation when the sound signal becomes lower than a predeterminedlevel and when the brightness signal has a predetermined value.
 14. Amethod of removing a part of an organic film from a surface of a rolleraccording to claim 12, further comprising the steps of making an imageof a roller surface with a CCD camera during the step of irradiating,processing the image to obtain a brightness signal, and stopping thelaser light irradiation and roller rotation when the brightness signalhas a predetermined value.
 15. A method of removing a part of an organicfilm from a surface of a roller according claim 12, further comprisingthe steps of detecting with a sensor sounds emitted during the step ofirradiating, converting the detected sounds into a sound signal, andstopping the laser light irradiation and roller rotation when the soundsignal becomes lower than a predetermined level.
 16. A method ofremoving a part of an organic film from a surface of a roller accordingto claim 10, further comprising the steps of making an image of a rollersurface with a CCD camera during the step of irradiating, processing theimage to obtain a brightness signal, and stopping the laser lightirradiation and roller rotation when the brightness signal has apredetermined value.
 17. A method of removing a part of an organic filmfrom a surface of a roller according to claim 10, further comprising thesteps of detecting with a sensor sounds emitted during the step ofirradiating, converting the detected sounds into a sound signal, makingan image of a roller surface with a CCD camera during the step ofirradiating, processing the image to obtain a brightness signal, andstopping the laser light irradiation and roller rotation when the soundsignal becomes lower than a predetermined level and when the brightnesssignal has a predetermined value.
 18. A method according to claim 9,wherein said step of irradiating uses multiple laser light sources. 19.A method of removing a part of an organic film from a surface of aroller according claim 18, further comprising the steps of detectingwith a sensor sounds emitted during the step of irradiating, convertingthe detected sounds into a sound signal, and stopping the laser lightirradiation and roller rotation when the sound signal becomes lower thana predetermined level.
 20. A method of removing a part of an organicfilm from a surface of a roller according to claim 18, furthercomprising the steps of making an image of a roller surface with a CCDcamera during the step of irradiating, processing the image to obtain abrightness signal, and stopping the laser light irradiation and rollerrotation when the brightness signal has a predetermined value.
 21. Amethod of removing a part of an organic film from a surface of a rolleraccording to claim 18, further comprising the steps of detecting with asensor sounds emitted during the step of irradiating, converting thedetected sounds into a sound signal, making an image of a roller surfacewith a CCD camera during the step of irradiating, processing the imageto obtain a brightness signal, and stopping the laser light irradiationand roller rotation when the sound signal becomes lower than apredetermined level and when the brightness signal has a predeterminedvalue.
 22. A method of removing a part of an organic film from a surfaceof a roller according claim 9, further comprising the steps of detectingwith a sensor sounds emitted during the step of irradiating, convertingthe detected sounds into a sound signal, and stopping the laser lightirradiation and roller rotation when the sound signal becomes lower thana predetermined level.
 23. A method of removing a part of an organicfilm from a surface of a roller according to claim 9, further comprisingthe steps of making an image of a roller surface with a CCD cameraduring the step of irradiating, processing the image to obtain abrightness signal, and stopping the laser light irradiation and rollerrotation when the brightness signal has a predetermined value.
 24. Amethod of removing a part of an organic film from a surface of a rolleraccording to claim 9, further comprising the steps of detecting with asensor sounds emitted during the step of irradiating, converting thedetected sounds into a sound signal, making an image of a roller surfacewith a CCD camera during the step of irradiating, processing the imageto obtain a brightness signal, and stopping the laser light irradiationand roller rotation when the sound signal becomes lower than apredetermined level and when the brightness signal has a predeterminedvalue.
 25. A method according to claim 1, wherein said step ofirradiating uses multiple laser light sources.
 26. A method of removinga part of an organic film from a surface of a roller according claim 25,further comprising the steps of detecting with a sensor sounds emittedduring the step of irradiating, converting the detected sounds into asound signal, and stopping the laser light irradiation and rollerrotation when the sound signal becomes lower than a predetermined level.27. A method of removing a part of an organic film from a surface of aroller according to claim 25, further comprising the steps of making animage of a roller surface with a CCD camera during the step ofirradiating, processing the image to obtain a brightness signal, andstopping the laser light irradiation and roller rotation when thebrightness signal has a predetermined value.
 28. A method of removing apart of an organic film from a surface of a roller according to claim25, further comprising the steps of detecting with a sensor soundsemitted during the step of irradiating, converting the detected soundsinto a sound signal, making an image of a roller surface with a CCDcamera during the step of irradiating, processing the image to obtain abrightness signal, and stopping the laser light irradiation and rollerrotation when the sound signal becomes lower than a predetermined leveland when the brightness signal has a predetermined value.
 29. A methodof removing a part of an organic film from a surface of a rolleraccording to claim 1, further comprising the steps of detecting with asensor sounds emitted during the step of irradiating, converting thedetected sounds into a sound signal, and stopping the laser lightirradiation and roller rotation when the sound signal becomes lower thana predetermined level.
 30. A method of removing a part of an organicfilm from a surface of a roller according to claim 1, further comprisingthe steps of making an image of a roller surface with a CCD cameraduring the step of irradiating, processing the image to obtain abrightness signal, and stopping the laser light irradiation and rollerrotation when the brightness signal has a predetermined value.
 31. Amethod of removing a part of an organic film from a surface of a rolleraccording to claim 2, further comprising the steps of making an image ofa roller surface with a CCD camera during the step of irradiating,processing the image to obtain a brightness signal, and stopping thelaser light irradiation and roller rotation when the brightness signalhas a predetermined value.
 32. A method of removing a part of an organicfilm from a surface of a roller according to claim 1, further comprisingthe steps of detecting with a sensor sounds emitted during the step ofirradiating, converting the detected sounds into a sound signal, makingan image of a roller surface with a CCD camera during the step ofirradiating, processing the image to obtain a brightness signal, andstopping the laser light irradiation and roller rotation when the soundsignal becomes lower than a predetermined level and when the brightnesssignal has a predetermined value.
 33. Equipment for roller machining andprocessing, comprising:a roller holding and rotating mechanism; a laseroscillator for generating and emitting a high intensity pulsed laserlight beam; a laser light irradiation mechanism constructed to irradiatea portion of a surface of a roller held in the roller holding androtating mechanism with light emitted from said laser oscillator,including at least one full mirror and at least one half mirror arrangedto divide the laser light beam into a plurality of sections, a pluralityof concave lenses arranged to broaden each of said light beam sectionsto produce a broadened section; a cylindrical lens arranged to shapeeach broadened section to produce a rectangular shaped beam; and amechanism which removes soot, film residue or other material generatedduring laser irradiation.
 34. An equipment for roller machining andprocessing according to claim 33, further comprising a sensor whichdetects sounds emitted when the roller is irradiated with the laser andconverts the detected sounds into a sound signal; and a controller whichsends out stop signals to stop laser light irradiation and rollerrotation when the sound signal becomes lower than a predetermined value.35. An equipment for roller machining and processing according to claim33, further comprising a CCD camera which makes an image of a surface ofthe roller when the roller is irradiated with the laser; a computerwhich processes the image made by the CCD camera and converts the imageto a brightness signal; and a controller which sends out stop signals tostop laser light irradiation and roller rotation when the brightnesssignal reaches a predetermined value.
 36. An equipment for rollermachining and processing according to claim 33, further comprising asensor which detects sounds emitted when the roller is irradiated withthe laser and converts the detected sounds into a sound signal, a CCDcamera which makes an image of a surface of the roller when the rolleris irradiated with the laser; a computer which processes the image madeby the CCD camera and converts the image to a brightness signal; and acontroller which sends out stop signals to stop laser light irradiationand roller rotation when the sound signal becomes lower than apredetermined value and when the brightness signal reaches apredetermined value.